NASA satellite snaps fireball 10 times more powerful than Hiroshima bomb
NASA has released images of a meteor exploding over the Bering Sea last December with a force over 10 times greater than the atomic bomb that destroyed Hiroshima in 1945. On December 18, 2018 at 23:55 GMT, the space agency's Terra satellite took a series of photos of a giant fireball exploding 16 mi (26 km) above the Earth's surface that is estimated to have released 173 kilotons of energy, making it the largest meteor blast since the Chelyabinsk incident of 2013.
If a meteor detonates in the Arctic with the magnitude of a medium yield nuclear device and there's no one to hear it, does it make a boom? That's the not very comforting question posed by the fireball exploding off the coast of Alaska as captured by five of nine cameras on the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard the Terra spacecraft.
According to Cornell University, the Earth is struck by up to 84,000 meteors over 10 grams in size each year, and many times more that are smaller than grains of sand. Almost all of these burn up high in the atmosphere, but NASA says that two or three times a century our planet is hit by meteors that are large enough and volatile enough to generate a city-smashing blast.
Fortunately, all of the known incidents in recent times that we know of happened away from populated areas, although the Chelyabinsk object that exploded high over Russia with the force of 30 Hiroshima bombs still caused property damage, and injured many people with flying glass and flash blindness. However, things could have been much worse if the blast had been closer to the ground or over a city center.
In other words, we've been lucky.
In the recent NASA images, the 173-kiloton Bering fireball shows up as an elongated orange-tinted scale left by the trajectory of the meteor as it burned up in the atmosphere, with its shadow visible against the lower clouds. The space agency says that fireballs are quite common and they are tracked by the NASA Center for Near Earth Object Studies database, but the vast majority of these are nothing more than small bursts that are more entertaining than dangerous.